Reland of [ESNext] Activate async/await for ClusterFuzz (patchset #2 id:40001...

Reland of [ESNext] Activate async/await for ClusterFuzz (patchset #2 id:40001 of https://codereview.chromium.org/2003503002/ )

Reason for revert:
All known async/await issues are fixed; turn back on Clusterfuzz

Original issue's description:
> Revert of [ESNext] Activate async/await for ClusterFuzz (patchset #1 id:1 of https://codereview.chromium.org/1992173002/ )
>
> Reason for revert:
> First CF feedback is in, reverting for now until the know bugs are fixed.
>
> Original issue's description:
> > [ESNext] Activate async/await for ClusterFuzz
> >
> > BUG=v8:4483
> > R=neis@chromium.org,littledan@chromium.org,caitpotter88@gmail.com
> > LOG=N
> >
> > Committed: https://crrev.com/c57cadfa09fa493141bf43c1c7b898187a71da19
> > Cr-Commit-Position: refs/heads/master@{#36362}
>
> TBR=littledan@chromium.org,caitpotter88@gmail.com,neis@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:4483
>
> Committed: https://crrev.com/eb059498b2b2d05731b0dce648bdab801d3873fd
> Cr-Commit-Position: refs/heads/master@{#36397}

TBR=caitpotter88@gmail.com,neis@chromium.org,mstarzinger@chromium.org,hablich@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:4483

Review-Url: https://codereview.chromium.org/2023003002
Cr-Commit-Position: refs/heads/master@{#36639}

src/flag-definitions.h

@@ -195,6 +195,7 @@ DEFINE_NEG_VALUE_IMPLICATION(harmony_shipping, intl_extra, true)
 // Activate on ClusterFuzz.
 DEFINE_IMPLICATION(es_staging, harmony_regexp_lookbehind)
 DEFINE_IMPLICATION(es_staging, move_object_start)
+DEFINE_IMPLICATION(es_staging, harmony_async_await)
 
 // Features that are still work in progress (behind individual flags).
 #define HARMONY_INPROGRESS(V)                                           \